Do cars really need to warm up first?

[JordanAndrew]

Just an article from Yahoo.




Winter driving tips - warming up the car
- Jeff Voth, Yahoo! Canada Autos
Those of us who live in a four-season climate are used to the idea of allowing our vehicles to warm up on a cold winter's day. But with the technology in today's automobiles, is this still something we should be doing? The simple answer is no. For the most part, letting your vehicle idle for long periods of time in the cold is not only bad for the environment, but can cause serious damage to your engine and emission system.

In the past, most vehicles employed a carburetor to deliver fuel to the engine. Today, almost all cars, trucks and SUVs on the road use some form of electronic fuel injection. In a cold engine, the computer management system tells the fuel injectors to stay open longer allowing more fuel to flow into the engine in part to keep the engine running cool. Trying to warm up the engine at slightly above idle speed is actually doing the reverse and inviting additional problems.

Cold engines produce a much higher level of unburned hydrocarbons as fuel needs heat to burn efficiently. Even the best catalytic converter is unable to process 100 per cent while running at maximum temperature, so allowing the engine to idle for extended periods of time can start to clog the system.

In addition, spark plugs may also become plugged or dirty due to inefficient fuel burning. Older vehicles required regular maintenance, calling for spark plugs to be changed every 30,000 km. Today, almost all engines employ an electronic ignition system that requires spark plugs to be changed at intervals in the range of 100,000 km. An engine at idle for extensive periods of time could dramatically shorten the life of your plugs, causing you to spend hard-earned money on unnecessary service and maintenance.

A better approach is to start your vehicle and let it run for up to one minute before driving away. This will allow fluids to begin flowing through the engine and then warm up to efficient temperatures under normal driving conditions.

Should the temperature outside dip below freezing, allow a maximum of four to five minutes of idle time before driving away. This should be just enough time to clean off any snow or ice that may have accumulated on the windows. While you may not be warm as toast on the way into work or school, you will benefit by saving money at the pump and garage and by driving a vehicle that runs cleaner and more efficient for many years to come.



http://ca.autos.yahoo.com/p/2052/winter-driving-tipswarming-up-the-car (http://)

[max_boost]

When it's really cold, 5 minutes and off I go.

[natejj]

Come join me in Yellowknife when its -45 and tell me not to warm up my car for 20 minutes....

[Cos]

Yes you need to warm up a car. If only to allow the oil pressure to drop and the oil to thin a bit.

[wintonyk]

i usually will give 1 or 2 minutes. Enough time to brush off the snow, run back in the house grab my gear than i am off. I don't let rpm go above 3000 until i am at normal temp though.

[sr20s14zenki]

10 minute warmups, fuck the environment :angel:

[ExtraSlow]

fuel is cheap, burn lots.

[JordanAndrew]

I usually just turn on the car, brush off the snow and I'm ready to go. Although when we do get around -25 or lower, I do warm up the car an extra minute or two. I'm the same with wintonyk though, I don't drive above 3,000RPM until it's fully warmed up.

[benyl]

haha.

Even on the coldest -35 day, I start and wait for the idle to drop (which is usually 30-45 seconds) and then drive off.

Heated seats FTW.

[Muji]

If my car is plugged in I give it a minute and drive off, keeping the RPM below 3K. Not plugged in and as cold as today, I let it idle for a few minutes. If I had heated seats, the time would be less I would think. I used to think a heated steering wheel was stupid, coming around to the idea these days.

[Supa Dexta]

I sleep in my truck some nights, I'll let it idle all night... :lol

[J-hop]

Originally posted by JordanAndrew
I usually just turn on the car, brush off the snow and I'm ready to go. Although when we do get around -25 or lower, I do warm up the car an extra minute or two. I'm the same with wintonyk though, I don't drive above 3,000RPM until it's fully warmed up.

x3, you actually don't want to let an engine sit their idling for long. Engine wear is the highest when the engine is cold. With some engines it could take 30+ mins of idling for the engine to reach op temp.

I read an article a while ago that stated you should let it idle only for a few mins and then drive it gently, this will help the engine reach op temp quicker and keep it out of the "wear zone". Also remember at idle you don't have much oil pressure and the old is thick (when cold), thick oil+low pressure = bad lubrication.

[SCHIDER23]

10 min max for me if I left the car I'm taking to work outside, usually i don't have much time to wait around lol, yea I like to squeeze every second of sleep, 30 to 40 sec if the car was in the garage.:thumbsup:

[luxor]

Originally posted by J-hop

Engine wear is the highest when the engine is cold.


FALSE information! Don't listen to this guy.

Engine wear is the highest at COLD START before the oil can reach the cylinder walls. BIG difference there man.


Originally posted by J-hop

Also remember at idle you don't have much oil pressure and the old is thick (when cold), thick oil+low pressure = bad lubrication.

Wrong again. Oil pressure when cold is actually much higher than your oil pressure at operating temperature. Please also read up on oil viscosity ratings before you claim oil is thick when cold, it's actually quite the opposite. Hint: 5W-30 oil is thinner when cold than at operating temperature.

[n1zm0]

Originally posted by luxor
Wrong again. Oil pressure when cold is actually much higher than your oil pressure at operating temperature. .

:werd: we had a rash of newbie pilots whining about high oil px indication snags this winter, those were all of who'm didnt let the engine warm up and shut it down within 30 secs of start up, ridiculars amount of paperwork to sign all due to lack of knowledge..

i want some of whatever J-hop is smoking :D

edit: but oil is not thinner in the cold, think about it, what happens to any syrup type liquid in the cold, take a jar and put molasses or honey in it, then put it outside overnight in -15 or colder.

in the high arctic, one of my bosses has pictures of him hanging on a DC-3's prop off the ground, the oil was pretty much a block of ice you couldn't even budge it.

[CapnCrunch]

Originally posted by luxor


Please also read up on oil viscosity ratings before you claim oil is thick when cold, it's actually quite the opposite. Hint: 5W-30 oil is thinner when cold than at operating temperature.

I think you need to do some reading. You can't actually be that clueless? :banghead:

[Abeo]

Originally posted by luxor

Wrong again. Oil pressure when cold is actually much higher than your oil pressure at operating temperature. Please also read up on oil viscosity ratings before you claim oil is thick when cold, it's actually quite the opposite. Hint: 5W-30 oil is thinner when cold than at operating temperature.

Oil does NOT become thinner as it gets colder. Multi-grade oil viscosity does not decrease as the temps go down, rather when the oil is cold it has the viscosity of a straight lighter grade oil (ie: 5W oil @ 0 deg C), and when its up to temp it has the viscosity of a heavier oil (ie: 30W oil @ 70 deg C). Multi-grade oil is thicker when cold, and thinner when hot, full stop.

[kvg]

Originally posted by Cos
Yes you need to warm up a car. If only to allow the oil pressure to drop and the oil to thin a bit.

Thats why I warm my car:thumbsup:

[THEMONK]

Because I HATE getting into and driving cold cars, Kelowna here I come.

[Twin_Cam_Turbo]

Originally posted by luxor


FALSE information! Don't listen to this guy.

Engine wear is the highest at COLD START before the oil can reach the cylinder walls. BIG difference there man.



Wrong again. Oil pressure when cold is actually much higher than your oil pressure at operating temperature. Please also read up on oil viscosity ratings before you claim oil is thick when cold, it's actually quite the opposite. Hint: 5W-30 oil is thinner when cold than at operating temperature.

Yes its highest at cold start followed secondly by the engine not being up to operating temperature. And im fairly certain 5W-30 oil is not thinner when its -30 then when its at operating temperature...

Personally if its not below -20 I let the car idle for about 15 seconds then drive gently with lower rpms until it is fully up to operating temperature. The other thing I try to do each drive is open the engine up fully when its warmed up all the way each drive.

[THEMONK]

Originally posted by CapnCrunch


I think you need to do some reading. You can't actually be that clueless? :banghead:

+1

[Tik-Tok]

Originally posted by Twin_Cam_Turbo


Yes its highest at cold start followed secondly by the engine not being up to operating temperature. And im fairly certain 5W-30 oil is not thinner when its -30 then when its at operating temperature...


It's less viscous, hence the 5W(inter) rating, VS 30. It's loaded with additives to keep the visocity low at cold temps.

5W is somewhere around 4cSt at 100*C Vs. 30 which is 10cSt @100*C

[CapnCrunch]

Originally posted by Tik-Tok


It's less viscous, hence the 5W(inter) rating, VS 30. It's loaded with additives to keep the visocity low at cold temps.

5W is somewhere around 4cSt at -25*C Vs. 30 which is 10cSt @100*C

The 5W rating has nothing to do with the 30. You guys need to read a bit.

Here you go.

http://www.supramania.com/aehaas/

[CapnCrunch]

Originally posted by CapnCrunch


The 5W rating has nothing to do with the 30. You guys need to read a bit.

Here you go.

http://www.supramania.com/aehaas/

Edit: Sorry misread your post but this still is a good read for anyone who thinks 5W30 is thinner when cold than it is when hot.

[TorqueDog]

No, you don't. Get in, start the vehicle, buckle seatbelt, find preferred radio station, then drive. You want to bring the motor up to its nominal operating temperature as quickly as possible.

Says it right in my owners manual as well.

That doesn't mean you can go WOT right off the bat, but who the fuck does that in winter?

[J-hop]

Thank you to those that clarified for me


Originally posted by luxor


FALSE information! Don't listen to this guy.

Engine wear is the highest at COLD START before the oil can reach the cylinder walls. BIG difference there man.


no I was referring to when the engine is cold, yes you are right there is a high amount of wear just as your start the engine before the oil has completely circulated properly (however short this period may be).

HOWEVER, when the engine is cold, one important factor is that the metal inside the engine has not expanded and tolerances are not tight therefore engine wear is high during the period when the engine has not reached op temp. In the case of v8s this can be a long ass time if you are sitting at idle with minimal heat being produced. Thus it is important not to leave a vehicle sitting idling at cold temperatures.


Originally posted by luxor

Wrong again. Oil pressure when cold is actually much higher than your oil pressure at operating temperature. Please also read up on oil viscosity ratings before you claim oil is thick when cold, it's actually quite the opposite. Hint: 5W-30 oil is thinner when cold than at operating temperature.

again you failed to understand what I was saying. Yes you are right oil pressure is slightly higher when the engine cold. HOWEVER you are sitting at idle, everyone knows not much oil pressure is produced at idle as compared to when you are driving at higher RPM. It doesn't matter that the oil pressure is higher when cold, you are still sitting at idle so you don't have much oil pressure.


please think about what you are saying before you post....

[ExtraSlow]

OK, tik-tok, I think you are close, but still a little bit off the truth here.
5W30 "acts" like a 5 weight oil when it's cold and then "acts" like a 30 weight oil when it's at operating temp.
The actual viscosity will be higher (thicker) when it's cold than when it's warm, but not quite as bad as a straight weight oil
That's what all those viscosity modifier additives do for you.

No motor oil has a higher viscosity at high temperatures.

[benyl]

Originally posted by CapnCrunch


The 5W rating has nothing to do with the 30. You guys need to read a bit.

Here you go.

http://www.supramania.com/aehaas/

*Will store motor oil in the house when I get home...*

Good read so far, on page 5.

[bituerbo]

I warm the Audi up and it's my 'summer' car, warm up the oil and allow proper lubrication to the turbo's before they spool.

Winter car is a fucking neon I bought for a thousand bucks. I'd start the car in Drive and with my foot to the floor if the auto-shitbox would allow me.

[n1zm0]

but anyways, the truth of the matter, cars these days are way more technologically advanced than they were in the carburetor days (which unfortunately i have to still deal with in the piston aircraft world), we really only warm up our cars for one reason: cause WE dont want to be cold.

heres what the feds say about warming up your car in winter:



Ask Canadian motorists why they idle their vehicles and you'll likely get a simple answer: to warm up the engine before they drive away. It's one of the most commonly held myths about driving in Canada. Excessively long warm-ups cost you money, waste fuel and generate unnecessary greenhouse gas emissions that contribute to climate change.

To assess the impact of vehicle warm-up, Environment Canada conducted a test program using a cold chamber and three vehicles. Each vehicle was cooled to -18°C and driven over a simulated urban driving cycle. The test procedure was performed using a 5-minute warm-up before driving the simulation urban cycle and repeated using a 10-minute warm-up before driving the simulated urban cycle.

The test results showed that with a 5-minute warm-up total fuel consumption increased by 7 to 14 percent and with a 10-minute warm-up total fuel consumption increased by 12 to 19 percent7. This also leads to a similar increase in carbon dioxide (CO2) emissions, as they are an unavoidable by-product of burning fossil fuels.

Contrary to popular belief, excessive idling is not an effective way to warm up your vehicle, even in cold weather. The best way to warm it up is to drive it. In fact, with today's computer-controlled engines, even on cold winter days, usually no more than two to three minutes of idling is enough warm-up time needed for the average vehicle before starting to drive – but make sure that windows are free from snow and properly defrosted before driving away!

Please consult your owner's manual or your vehicle service advisor if you would like a recommendation specific to your vehicle or climatic conditions.

Unfortunately, some motorists warm up the engine to the point where the car heater has warmed the interior of the vehicle. On cold days, this could take upwards of 10 minutes and, as can be seen from the tests, will have a significant impact on fuel consumption and emissions of carbon dioxide (CO2), the principle greenhouse gas.

What's often forgotten is that idling warms only the engine – not the wheel bearings, steering, suspension, transmission and tires. These parts also need to be warmed up, and the only way to do that is to drive the vehicle. Until the engine temperature begins to rise, it's a good idea to avoid high speeds and rapid acceleration. It's also important to ensure that windows are free from snow and properly defrosted before driving away!



http://oee.nrcan.gc.ca/transportation/idling/warm-up.cfm?attr=8

[89s1]

they mention twice in that blurb to be sure your windows are free of ice and snow, yet every day it snows I see some asshat that can't be bothered to take the 45 seconds to brush the snow off and is driving blind like a fucking retard.

[ricosuave]

Originally posted by THEMONK
Because I HATE getting into and driving cold cars, Kelowna here I come.

um...

you DO know it does actually get cold in Kelowna in the winter, right?

http://www.theweathernetwork.com/weather/cabc0149

[revelations]

I wait until the coolant gauge reads +15c -- which could be 60 seconds in this weather -- then I drive away using partial throttle only until the engine reaches normal operating temp (my civic, +80c) .

[theken]

I warm up till my window is defrosted. Or the snow is melted off so I have no ice

[01RedDX]

.

[prae]

Originally posted by 01RedDX
This one idiot at Pennzoil lube place in Bowness (AVOID) argued with me and kept insisting that 10W30 and 5W30 are totally interchangeable, even tried to ignore the recommended 5W30 in bold letters on my engine oil cap.

well, at most temperatures 10W30 and 5W30 ARE basically interchangeable.

Once your engine is at operating temp there is no real difference. It's cold starts where 5W/10W are different.

That said, I always try to run the recommended weight of oil in my vehicles..

[Accord_tunerx]

wait....its takes my v8 to warm up 10mins. i alwasy warm up my cars or suv before taking off.

[01RedDX]

.

[Canadian 2.5RS]

Originally posted by natejj
Come join me in Yellowknife when its -45 and tell me not to warm up my car for 20 minutes....

Been there...Done that!

[Cos]

.

[msommers]

I let her warm up for a few minutes if it's colder than -10 and then baby the shit out of it until it warms up. Tranny seems to warm up faster that way too

[Unknown303]

I start it and drive it. Take it easy until the engine comes up in temperature. That's about it.

[Gollum244]

ive got a carb...if she starts i let her warm up for a while. neighbors hate me for it, but oh well.

[boarderfatty]

I will let mine warm up for 5-10 minutes. I don't wait for it to get to min operating temp but I will let it drop from high idle to low idle. that alone takes 5-10 minutes. My Porsche has close to 12 liters of oil and the same for coolant, so to get that warm enough to drop from high to low idle takes a while.

I have heard the recommendation to drive it right away, and I have done it with all my other cars, start it and drive it under 3k rpm until its at operating temp. But the porsche drives like shit while still on high idle so I will wait for it to drop before driving it below 3k rpm until it hits operating temp.

[Toma]

:nut:

Wear on a motor is highest when the engine is cold and UNDER LOAD. Never drive a cold engine.

Also, oil temperature must come up in order for proper lubrication AND for the bearings, rods, crankshaft, piston pins, bores etc to open up to proper running clearances.

Cold motor under load = increased wear. Pretty "captain obvious"

Ditto fuel economy. A cold engine is still under warm up enrichment and runs rich for a while.... Software I have worked with, MOST newer engines will not enter closed loop till they are over 120ºor 140 F

That and some newer cars with variable cam timing etc... none of that starts working till they reach a certain temperature, and the motors are less efficient.

Motors use hardly ANY gas idling. Fuel consumption goes up exponentially with load and the square of acceleration rate.

At idle, your fuel flow maybe .05 pounds of fuel a minute.... driving cold (gonna assume no accel, just cruise in snow at about 30k/h)? I betya easily doin some quick math .3 pounds per minute. Driving warmed up? maybe .17# of fuel per minute.... just guesses based on fuel flows I have observed on the dyno.

So determining at what time point its best to transition from idle to driving would depend on a LOT of factors, and not as cut and dry as all these fucking idiot "experts" like to make it out to be.

An actual study would have to be done to pinpoint the point where idling for x amount of time is more wasteful than driving it cold. It would have to be done at various starting temperatures, and various total commute times.

Anything under about 0, I warm my car up 10 minutes for care of the engine but mostly cause I like a warm car, who's windows are defrosted in and out, and the steering wheel isn't cold on my fragile hands ;)

[Cos]

^ stop making sense. You are ruining the thread

[Unknown303]

It's his atkins diet that's making him smarter.

[jwslam]

Originally posted by Unknown303
I start it and drive it. Take it easy until the engine comes up in temperature. That's about it.

+1


Originally posted by benyl
Heated seats FTW.

+1

[5000Audi]

when i get up to go to work on monday i let my truck run for 10 mins while watching the weather network.. then to work... plug in truck... start work truck... let warm for around 30 mins.. then she isnt shut down till friday evening.. runs 24 hours a day 5 days a week... idles at 800rpm for 40-50 hours a week when sleeping haha

[J-hop]

yea at the camp I was at a couple summers ago the guys have to do that in the winter especially with the diesels, they don't start so well at -40 and below

[georgemagana]

Originally posted by TorqueDog
No, you don't. Get in, start the vehicle, buckle seatbelt, find preferred radio station, then drive. You want to bring the motor up to its nominal operating temperature as quickly as possible.

Says it right in my owners manual as well.

That doesn't mean you can go WOT right off the bat, but who the fuck does that in winter?

Hope thats only bad wording. You wanna get your car to normal operating temperature as slow as possible. I didnt see anyone here talking about thermal shock and thermal expansion, maybe i just didnt see it but it can cause severe damage to engine as well as poor lubrication and all the things mentioned above. So you wanna give your car maybe about 2 to 3 minutes ( i personally wait for the rpm to drop to 1200 which takes about 2 or 3 minutes) and the go slowly NEVER driving above 3000 rpm. Thats why some cars come with a rpm limitter that shuts the gas off when driving at high rpm when cold.

[Tram Common]

Alright guys, let's learn about engines today.

A closed loop is after the 02 is warmed up and it uses the signals from the oxygen sensor and adjusts fuel trim accordingly... thus more efficiently.

An open loop is more for cold start ups until the oxygen sensor is warm enough to function, usually dumps more fuel at cold start to help combustion.

BOOM! Now ya'll is in the know!

Also, I let my car idle forever because I don't like driving a cold ass car, no matter what the downfall... besides, this is Beyond, the majority of us drive POSs that will likely blow up due to some retarded mod well before they will ever break from cold starts and excessive idling.

[J-hop]

also remember that 02s don't function properly until they are brought up to temp. most newer cars will have a heater circuit on the O2 but older (mid 80s and earlier????) often won't.

[davesparky6]

Start the car, let it idle for a minute or two, then drive gently.
Keep in mind that there are other things that need to be brought up to temp; like the tranny and diffs.
Idling your car for 15 minutes and then driving like a maniac is bad for these components.:thumbsdow

[spike98]

The remote start in the jetta is set to 15 min and i often hit the button to start it for an extra 5 min before heading to work.

This, coupled with the block heater plugged in at any temp below 0C makes for a toasty car on my daily commute.

Toma, in everyone of your non-auto related posts you come off as a bat shit crazy lunatic. However, when it has an engine, you fucking know your shit! I agree with your post.

[CapnCrunch]

Short answer is your vehicle only need about 30 seconds even on the coldest days. Unless you live off of a highway at the very bottom of a 2km long hill, driving gently for the first 5 minutes is the quickest way to warm it up.

I usually warm my truck up for 5 minutes on super cold days, otherwise I can't get the windshield to clear. -10 or warmer I start her up and go.

[texasnick]

When I first got the GT4 I would let it warm up to temp before driving it. I found I would get slight missing when I did that and I think the excessive idling was fouling the plug(s) slightly. Also, after reading about gasoline dilution while idling, I decided it's probably not the best idea to let it sit running that long.

Nowadays I start it up and let it idle until the car thinks the coolant is at least warm enough to start blowing heat out of the vents via climate control. Once it starts the fan and blows heat, I figure it's good to drive with a very light foot until about 5 mins or so after the water temp gets up to normal. Until then, I never rev about 3,000 rpm or so and I never ever boost until I'm sure the oil is up to temp.

[benyl]

You guys all talk about coolant being up to temp, but it is the oil temp that matters.

I see it everyday (I have both a coolant gauge and oil temp gauge). Coolant hits 95C when the oil is still at 50C. Oil is only good at 80c or higher. It takes me nearly 10kms to get the oil temp that.

The heater starts blowing hot at 45C coolant temp and the oil is still 15C.

It takes a while to get the oil up to temp before you can romp on it.